The missing link: elders’ sleep and memory issues

Dad’s memory varies greatly. For instance, last week he could remember the first name of a woman he had read about in a 2010 newspaper article. But yesterday he couldn’t remember that we had to hire a plumber last week — even though he was the one who noticed that we had a backed-up sink.

I’m not worried, however, that he has some sort of dementia. Instead, I believe his memory issues are primarily due to his difficulty sleeping soundly throughout the night.

Sleep and memory

Sleep is critical for memory and learning, the National Institutes of Health (NIH) explains. During sleep, the brain goes through different cycles, which repeat approximately every 90 minutes. The different phases encompass light sleep, deep sleep and rapid eye movement (REM) sleep, which is often associated with dreaming.

The non-REM sleep stages are believed to prime the brain for learning. Researchers believe that lack of sleep can lower the ability to learn by as much as 40 percent. Furthermore, sleep allows the brain to go back through recent memories to decide what to keep and discard. Memories tend to become more ingrained in the brain during the deep stages of sleep. Then the REM stage is believed to link together related memories, often in unexpected ways.

Sleep and aging

MedlinePlus, a service of the U.S. National Library of Medicine, reports that altered sleep patterns often accompany aging. Seniors tend to have more difficulty falling asleep and may awaken more often (which is what Dad experiences), and may also spend less time in deep, dreamless sleep.

And it’s the lack of good sleep that causes issues. The NIH article mentions that adults over 60 had a 70 percent loss of sleep when compared to young adults between the ages of 18 and 25. It turns out the deep sleep that strengthens memories begins to decline when a person is in their late 30s.

Finding the path to Dreamland

In the NIH article, Harvard Medical School sleep expert Dr. Robert Stickgold says that restoring sleep may help memory in the elderly. So what could help an older individual find a more satisfying night’s sleep? The Mayo Clinic recommends the following steps: